The 'Scott Pilgrim vs. the World' star - who married long-time girlfriend Brady Cunningham in July 2009 - has revealed the couple became proud parents to a daughter, Marlowe Rivers Schwartzman, on December 4.

Announcing his wife's pregnancy last autumn, Jason said: "I'm lucky I found a woman that I love and that's amazing. I'm having a family and I feel very happy. I try to be a good father-to-be.

"I try to treat my wife well so she can enjoy these months."

However, the 30-year-old actor recently admitted he had decided to grow a moustache in preparation for the new arrival so he can embarrass his daughter in years to come, and was inspired by the sizeable facial hair of his own father, composer David Shire.

He said: "I decided to grow out this moustache, so when we take photos, my boy or girl, whatever it is, they will be embarrassed. So I am now thinking of ways to embarrass my unborn child.

"I would show my friends, 'Look at my father's moustache, how terrible is that?!' "